They studied three killer whales living in an aquarium in France. In each test, they instructed one of the whales to imitate an action that another was performing. Each whale learned the “do that” command within 20 attempts.

Once the whales knew what “do that” meant, Abramson instructed them to imitate 15 behaviours that they already knew, such as slapping the water with their pectoral fins. They were also asked to imitate four that they had never seen or attempted before, such as barrel rolls. The whales took no more than eight attempts to imitate a familiar behaviour, and even the new behaviours never took more than 16 tries.

Nevertheless, the whales’ imitative skills could help explain why different groups use such varied strategies. As soon as one whale develops a new hunting technique, the others will quickly pick it up. If that’s what’s going on, killer whales join bottlenose dolphins in a small group of marine mammals that have cultural traditions.